Electrical connector and sealing means therefor



j? 38 40 a Za 4Z 4g p42 43 Nov. 1, 1960 M. c. LOGAN ETAL 2,958,723

ELECTRICAL CONNECTOR AND SEALING MEANS THEREFOR Filedkoct. 2, 1957 nited States Patent O ELECTRICAL CONNECTOR AND SEALING MEANS THEREFGR Filed Oct. 2, 1957, Ser. No. 687,805

1 Claim. (Cl. 174-84) The invention relates to insulated connectors of the type utilizable for joining bare end portions of a pair of insulated wire conductors in spaced, coaxial relation to form an approved mechanical and electrically conductive joint therebetween by means of a known crimping operation and wherein the bare ends of the conductors are visible by means of an inspection window intermediate the ends of the connector.

More specically, the invention resides in a sleeve type connector wherein a conductive metal sleeve having a wall portion cut-out centrally thereof is disposed within a substantially transparent plastic sleeve of relatively greater length in fixed telescopic relation and forming a window over said cutout portion, each end of the plastic sleeve having a tapered, rubber-like, resilient sleeve plug frictionally inserted therein whereby, upon the intrusion ofa stripped end portion of an insulated wire conductor through each sleeve plug into the respective ends of the metal sleeve, a fluid tight seal is formed on and about the .entire periphery of the insulated portion of each conductor extending through said sleeve plugs.

In ,analogous sleeve type connectors, as known heretofore, the respective end portions of the outer plastic sleeve, usually of nylon, were deformed substantially on and about the insulation covering on a pair of coaxially related wire conductors intruded therein, by crimping a short metal ferrule on the outer periphery of the respective ends of the plastic sleeve, whereby to cold ow the end portions thereof on and about the intruded conductor portions in uid sealing relation. However, such connectors possessed certain disadvantages by reason of the fact that in crimping the free end portions of the nylon sleeve on the intruded conductors, the nylon did not flow uniformly or completely about the periphery of the insulation covering of the intruded conductors with the result that a satisfactory fluid-tight seal therebetween was not obtained.

The present invention obviates the aforesaid disadvantages by the provision of a rubber-like resilient sleeve plug, having an internal and external taper, which is frictionally force-fitted one into each end opening of the outer plastic sleeve whereby when a stripped end portion of an insulated wire conductor is forced through each of the respective sleeve plugs, an effective annular seal therebetween is obtained by reason of the fact that the smallest inner diameter of each sleeve plug, disposed Within the plastic sleeve, is always, in all sizes of the connector and its correlated sleeve plugs, less than the overall diameter of the intruded conductors, whereby an annular fluid-tight seal therebetween is readily obtained.

Accordingly, it is an object of the invention to provide an improved sleeve type connector which is not subject to the above-noted disadvantages.

Another object of the invention is to provide an improved sleeve type connector including resilient sleeve means therein, whereby the respective ends of the connector are automatically sealed against the entrance of 2,958,723 Patented Nov. 1, 1960 ice moisture by the intrusion of an insulated wire conductor of predetermined diameter, into each end thereof.

A further object of the invention is to provide an improved sleeve type connector as specified which does not require a mechanical crimping operation to seal the respective ends thereof on a pair of insulated conductors intruded therein.

Another object of the invention is to provide an improved sleeve type connector as specified wherein the inner metallic sleeve and the outer plastic sleeve coact, in assembled telescopic relation, to prevent relative endwise movement of the metallic sleeve within said plastic sleeve.

A further object of the invention is to provide an improved sleeve connector of the non-through type wherein portions of the inner metal sleeve, centrally thereof, provide stops for limiting the intrusion of a Wire conductor into the respective ends thereof.

Another object of the invention is to provide an improved sleeve type connector as specified wherein the wall thickness of the Outer plastic sleeve is reduced centrally of its length to enhance the transparency thereof.

A further object of the invention is to provide an improved sleeve type connector as specified wherein the outer plastic sleeve includes a pair of spaced, circumerential anges integral therewith and adapted to selectively coact with a complementary crimping tool for properly locating the connector therein preparatory to crimping portions of the metal sleeve on the stripped ends of a pair of intruded insulated conductors.

With the above and other objects in view, the invention resides in the novel construction, combination, and arrangement of parts, the novel features of which are set forth with particularity in the appended claims, the invention itself, however, both as to its organization and method of operation, together with additional objects and advantages thereof, being best understood from the following description of a specific embodiment thereof, when taken in connection with the accompanying drawing, in which:

Fig. l is a view in elevation of the insulated sleeve connector showing a resilient sleeve plug frictionally fitted in each end portion thereof;

Fig. 2 is an end view of the insulated sleeve connector shown in Fig. l;

Fig. 3 is a longitudinal sectional view of the insulated sleeve connector and the resilient sleeve plugs frictionally fitted in the opposite ends thereof;

Fig. 4 is a longitudinal sectional view similar to Fig. 3, showing a stripped end portion of an insulated conductor intruded into each end of the connector through its correlated sleeve plug;

Fig. 5 is a longitudinal sectional view similar to Fig. 4, showing the respective insulated end portions as crimped within the inner metal member of the connector; and

Fig. 6 is a longitudinal sectional view similar to Fig. 3, showing a modified form of the spaced annular flanges about and intermediate the ends of the insulating sleeve.

Referring to the drawing, the hereindescribed insulated, two-way connector, generally indicated at lll, comprises a cylindrical member 12, of highly conductive metal such as soft copper, for example, a thermoplastic sleeve 14, of substantially transparent plastic such, for example, as nylon, frictionally fitted thereon in telescopic relation, and a rubber-like sleeve plug frictionally fitted in each end lof the plastic sleeve 14, for a purpose presently to be described.

As best illustrated in Fig. 3, the cylindrical metal member '12 is provided with an axial bore 18 of predetermined diameter extending inwardly from each of its respective ends to a point short of the mid-length thereof, to define opposed conical inner ends Z0, lthe outer op- 'posite end of each of said bores 18, being suitably counterbored, as at 22, whereby a stripped end portion of an insulated wire conductor C of smaller size or diameter may' be freely intruded in each of said bores 18 to the depth thereof, withthe adjacent end portion of the insulation covering on said conductors intruded in the counterbored end portions 22 of the bores 18.

Further in accordance with the invention, a semi-circular void 24 of predetermined length is formed in the periphery of the cylindrical metal member 12, centrally f its opposite ends in intersecting relation with its axial center, whereby to expose to view the remaining onehalf of the circumference of each of the inner ends 20 of the bores 18 in the member 12, presenting opposed substantially inclined shoulders 26 adapted for engaging and limiting the intrusion of a conductor end portion into each of the bores 18 in the cylindrical metal member 12, as aforesaid. Thus, the substantially transparent like resilient sleeve' plug 42, having an annular flange 44 at one end thereof to provide a shoulder thereon, is fricplastic sleeve 14, which is telescoped over the metal member 12, coacts with thevoid 24 formed therein to form an inspection window 28 in the connector 10.v

VAs best shown in Figs. 3, 4 and 5, that portion of the outer plastic sleeve 14 overlying the void 24 formed centrally of the conductive metal member 12, presents an annular wall thickness which is less than the thickness of the adjacent wall portions, as indicated at 30, whereby to enhance the transparency of that portion of the outer plastic sleeve 14, to facilitate inspection of the inner half ends of the respective bores 18 in the conductive metal member 12, as will be understood.

As illustrated throughout the several views in the drawing, the length of the plastic sleeve 14 is always such that its opposite end portions 32 extend beyond the opposite ends of the inner metal member 12, for a purpose hereinafter described.

Further in accordance with the invention, the outer periphery of the plastic sleeve 14 is preferably, although not necessarily, provided with a pair of spaced annular flanges 34, formed integral therewith intermediate the ends thereof for the purpose of reinforcing the plastic sleeve 14 against the forced insertion therein of the metal member 12. The annular flanges 34 are also adapted to serve as a means for spacing a plurality of such connectors 10, When hunched together in multi-electrical conductor connections, as in large aircraft assemblies and the like, for example, and also adapted to serve as a means for quickly locating a connector 10 in proper position transversely of the jaws of a known form of crimping tool or the like, for crimping spaced portions 'of the conductive metal member 12, on the stripped end portion of an electrical conductor intruded thereinto :from each end thereof.

Alternatively, the width yof each of the annular flanges 34, formed about the plastic sleeve 14, may be substantially divided by means of a narrow annular groove 36 therein, as illustrated in Fig. 6, whereby to facilitate possible elongation or stretching of the nylon sleeve 14, lengthwise of its axial center, particularly in the region of said annular flanges, in response to a crimping operation on the conductive metal member 12, at spaced points thereon and through the plastic sleeve 14, in

known manner. Y

In order to prevent relative endwise movement of the conductive metal member 12 within the outer plastic sleeve 14, the annular edge at each end face of the inner metal member 12 is substantially flared outwardly, as indicated at 38, by means of a suitable internal up- :setting operation simultaneously on each end of the met- .al member 12 to expand corresponding regions of the Louter plastic sleeve 14, in response thereto, whereby an .annular groove 40 is formed internally ofthe plastic Lsleeve 14, about each ared end 38 of the metal member 12, whereby the member 12 is held in assembled position,

as will be understood.

.Further Ain accordance with the invention, a rubbertionally force-fitted into each open end portion 32 of the outer plastic sleeve 14, with the shoulder provided by its annular flange 44 substantially in abutment with the end face thereof, whereby to provide a ud-tight seal between the inner peripheral Wall of each open end portion 32 of the plastic sleeve `14, and the insulation covering on a conductor end portion C, when intruded through each sleeve plug 42 with its stripped or bare end portion in abutting engagement with one of the inclined shoulders 26 deiined by the inner end 20 of each of the bores 18, provided therefor in the conductive metal member 12.

VThe outer periphery of each of the resilient sleeve plugs 42 is of uniform diameter, as at 48, for a distance of at least one-sixteenth of an inch from the shoulder formed on one end thereof by the annular flange 44, and corresponds substantially to the inner diameter of the respective end portions of the plastic sleeve 14. The outer periphery of the opposite end of each sleeve plug 42 is of a uniform reduced diameter, as at 50, for a distance Vof at least one-sixteenth of an inch, from which the intermediate outer periphery of each sleeve plug 42 tapers to the larger uniform diameter 48 adjacent the annular flange 44. It is to be noted that the outer diameter of the anged end 44 of the sleeveplugs 42 is at least equal to the outer diameter of the respective end portions 32 of the connector 10, in all sizes thereof.

` The inner periphery of each of the resilient sleeve plugs 42 vis constituted by an axial opening 52 therethrough having a uniform diameter at the smallest end thereof, as at 54, which is less than the size or over-all diameter of the insulated conductor C to be passed therethrough, and having a length of at least one-sixteenth of an inch from which the opening 52 tapers uniformly outwardly to the opposite flanged end of each sleeve plug 42 Where the maximum diameter of the opening is greater than the over-all diameter of the insulated wire conductor C.

Accordingly, when the hereindescribed connector 10, including the resilient sleeve plugs 42 intruded in the respective end portions 32 thereof, is to be utilized for forming a connection between a stripped end portion of each of a pair of insulated wire conductors in spaced coaxial relation, each conductor C is passed through one of the resilient sleeve plugs 42 into each of the respective bores 18, provided therefor in the conductive metal member 12 as and for the purpose described.

From the foregoing, it will be readily apparent that the outer uniform diameter 48 of each sleeve plug 42 seals the lopen end portions 32 of the connector 10, and that the smallest end opening 54 of each of the sleeve plugs 42 is sealed by the forced passage therethrough of the insulated end portion of the wire conductors C. It is to be observed that the diameter or size of the insulated conductors C, to be used with each connector 10, is always larger than the size of the smallest end opening 54 in each sleeve plug 42. Thus, the smallest end opening 54 of the sleeve plug 42 is always distended by the passage therethroughof the insulated portion` of theconductor C, whereby a uidtight seal is effected on yand about the insulation covering on eachof the conductors C intruded into the connector 10, and the end portions 32V thereof thus lsea-led indirectly on the intruded conductors in fluidtight relation. Moreover, it will also be apparent that the novel sleeve plug 42, provided in each end portion' 32 of the rconnector 10, provides -a resilient sealing means therefor which permits larger sizes of insulated conductors, within a limited range, to be utilized with each given size of the connector 10 and its associated sleeve plugs 42 in accordance with the invention herein illustrated and described. l

While the invention has been illustrated and described with respect to a preferred embodiment thereof, it is to vbe expressly understood that various changes, modifications and substitutions in the material and/or construction of the improved electrical connector and the sealing means therefor may be made without departing from the inventive concept underlying the same. Therefore, the invention is not to be limited except as is necessitated by the prior art and the scope of the appended claim.

I claim:

In combination with an electrical connector comprising a cylindrical member of ductile conductive metal having a bore in each end portion thereof terminating short of its mid-length and adapted to be crimped on a bare end portion of a pair of insulated wire conductors intruded therein in spaced coaxial relation, said metal member having a semi-circular void in the periphery thereof centrally of its opposite ends to expose the respective inner ends of said bores, a substantially transparent plastic sleeve of relatively greater length and uniform internal diameter having an integral, annularly grooved flange about its outer diameter adjacent each end thereof and a reduced wall thickness mid-way thereof to increase its transparency, force-fitted over said metal member with its opposite end portions extending beyond the respective ends of said metal member and its reduced wall thickness coacting with the void in said metal member to provide an inspection window in said connector, of a tapered bushing of resilient rubber-like material having an annular flange on one end thereof and a short uniform outer diameter, extending from said flange to a point midway of its length, corresponding substantially to the inner diameter of the open ends of said plastic sleeve, frictionally 6 iitted in each end thereof in fluid-tight relation with its annular ange in abutment therewith, the remaining outer periphery of -said bushing tapering from said mid point to a short uniform outer diameter smaller than the inner diameter of the extended open ends of said plastic sleeve whereby the intruded end of said bushing is adapted to be distended by the passage therethrough of insulated conductors of varying larger idameters, said bushing having a tapered axial opening in its flanged end portion terminating substantially midway of its length in a short uniform inner diameter smaller than the outer diameter of the insulated conductor to be extended therethrough whereby to provide a fluid-tight seal about the periphery thereof.

References Cited in the le of this patent UNITED STATES PATENTS D. 181,302 Logan Oct. 29, 1957 1,933,555 Jasper Nov. 7, 1933 2,225,472 Franklin Dec. 17, 1940 2,760,579 Kabakoi Aug. 28, 1956 2,772,034 Richmond Nov. 27, 1956 2,774,810 Ritter Dec. 18, 1956 2,806,214 Forney Sept. 10, 1957 2,809,365 Broske Oct. 8, 1957 OTHER REFERENCES Publication I: Recent Developments in the Use of Polythene Cables for Subscribers Lines (Waddon), published in The Post Oice Electrical Engineering Journal, vol. 50, No. 4, Ian 1954 (pages 219-221 relied on). 

